Journal of Cleaner Production
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2022
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IF 11.072
Changsong Zhao,Yongpeng Wang,Mengxi Cheng,Hailing Zhang,Yuanyou Yang,Ning Liu,Jiali Liao
Column reactors and batch experiments were conducted to investigate the performance and mechanism of uranium (U) immobilization enhanced by extracellular polymeric substances (EPS) from anaerobic granular sludge (ANGS). Successful remediation of anoxic U-contaminated groundwater was achieved using ANGS-inoculated column reactors (all higher than 98% of U removal rate for the three columns at hydraulic retention time of 72-h), and parameters (hydraulic retention time, nitrate content, the type and content of the external carbon sources) influenced the reactor performance. 306-day column studies implied the enhanced U immobilization by EPS, where EPS acted as energy source, electron donors and U reservoir with a contribution of 3.5–6.8% to total U removal by ANGS. Results in 26-h batch experiments further demonstrated that U immobilization performance of ANGS could be promoted (6.4–22%) by EPS through adsorption and reduction. EPS induced the precipitation of U(VI) and U(IV) particulates, and amino and carboxyl groups were the main functional groups for EPS binding with U. Complexation was confirmed between humic acids in EPS and U. The interaction mechanisms between U and EPS were directly evidenced to involve complexation, induced particulate formation and reduction.
研究领域:
环境科学
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微生物学
✓ 已验证
DOI
高影响因子
BIOCHEMICAL ENGINEERING JOURNAL
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2013
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IF 2.579
Zhongjie Wu,Wei Qi,Mengfan Wang,Yuefei Wang,Rongxin Su,Zhimin He
The ceramic powder with high metal content (MCP) was prepared as a new kind of immobilization carrier. Cu-MCP showed the best affinity to α-amylase and exhibited maximal activity. The effects of metal content, chelation time and amylase concentration on Cu-MCP-amylase activity were investigated. Under the optimal preparation conditions (the ratio of metal hydroxide precipitation to matrix (P/M): 0.23, chelation time: 8 h and amylase solution: 2.2 g/L), the activity of Cu-MCP-amylase could reach 31.5 U/g (54.5% of activity yield). Then, both Cu-MCP and Cu-MCP-amylase were characterized by XRD, SEM, BET-N 2 and FTIR. These characterizations confirmed that the Cu-MCP was a superior carrier with significant mechanical strength, considerable surface area, stable environment, homogeneous surface and low cost. Meanwhile, it also indicated that amylase had been efficiently immobilized on the external surface of Cu-MCP. Next, the properties of Cu-MCP-amylase were determined. It had optimal pH 7.0 and optimal temperature 70 °C with improved thermal stability. Finally, Cu-MCP-amylase showed significant catalytic capacity and stability in a column reactor, which could retain 80% of initial catalytic capacity after 40 recycle times.
研究领域:
生物化学
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酶工程
✓ 已验证
产品关联
DOI
高影响因子
Chemical Engineering and Processing-Process Intensification
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2025
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IF 3.9
Shuang Wang,Weicheng Pan,Haijiang Zhang,Hao Chen,Rong Chen
To enhance the mass transfer and organic pollutants oxidation in the plasma bubble column reactor (BCR), a Venturi tube was utilized to produce flowing wastewater containing plasma microbubbles by hydrodynamic cavitation (HC) effect. Meanwhile, the convection of wastewater was optimized through adjusting Reynolds number at the throat of the Venturi tube ( Re T : 5870 – 56,300). The variation of C v and ΔP with the Re T revealed the starting point of the HC at the Re T of 24,600 (210 L·h -1 ). The HC effect reduced the minimum plasma bubble size d to 100 μm and increased the gas holdup of plasma bubbles (11 %). Comparing the plasma bubbling mode without liquid flow, energy yield ( EY ) of plasma degradation (2333 mg·kWh -1 at the removal of 90 %) and the volumetric mass transfer coefficient ( k l a = 0.037 s -1 ) was improved by 1.63 and 3.08 times, respectively. The dimensionless mass transfer correlation among Reynolds number Re (220 – 2113), Froude number Fr (0.0019 – 0.0075), initial concentration difference ( c 0 / c 50 : 0.5 – 2.0), and Sherwood number Sh in the HC-BCR have been established. This study provides insights to optimize the convection of wastewater in the HC channel for the enhancement of plasma oxidation in the BCR.
研究领域:
环境科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
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2023
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IF 5.3
Hong Yao,Houfang Lu,Kejing Wu,Yingming Zhu,Binshen Wang,Yingying Liu,Yijiao Qiu,Bin Liang
Biphasic solvent 3-dimethylaminopropylamine (DMAPA)/poly(ethylene glycol) dimethyl ether (NHD)/H2O solution is a promising absorbent for CO2 capture. The kinetics of CO2 absorption in both DMAPA/NHD/H2O system and DMAPA/H2O systems was investigated and compared in a wetted wall column reactor with different CO2 loadings at different CO2 partial pressures from 30 to 70 °C. The equilibrium CO2 loadings were also determined. Meanwhile, the density and viscosity for both systems were measured. In both systems, the mass transfer flux of CO2 increases linearly with the increase of CO2 partial pressure. The kinetic data were interpreted by the zwitterion mechanism. The overall mass transfer constant was determined according to the absorption rate experiments performed in the pseudo-first-order regime. The overall mass transfer resistances increase with the increase of CO2 loading and decrease with the increase of temperature. The addition of NHD decreases the equilibrium CO2 loadings at the same CO2 partial pressure and temperature. However, it increases the enhancement factor significantly and can promote both the absorption and the desorption process. It provides basic information not only for the further utilization of DMAPA/NHD/H2O solution, which is helpful for the design of absorption reactor, but also for developing new phase-change absorbents for CO2 capture.
研究领域:
化学工程
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
WATER RESEARCH
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2018
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IF 7.051
Da Wang,Haodan Xu,Jun Ma,Stefanos Giannakis,Xiaohui Lu,Huizhong Chi,Shuang Song,Jingyao Qi
A light-weight granular mixed-quartz sand (denoted as L-GQS) combined with stirring-assisted bubble column reactor was firstly applied in catalytic ozonation of atrazine. The L-GQS, with a density of 2.36 g cm −3 and average diameter of ca. of 4 mm, was readily churned up and uniformly distributed within the solution in the reactor. The introduction of L-GQS was found to exhibit enhanced catalytic ozonation of atrazine, with the increase in degradation rate and the dissolved organic carbon (DOC) removal being more than 2-fold for the catalytic process (L-GQS dosage = 5 g L −1 , [atrazine] 0 = 50 μM, [O 3 ] = 25 mg L −1 , gas flow = 0.2 L min −1 , at pH 7.0 and 293 K). The L-GQS settled at the bottom of the reactor after experimentation, allowing its easy separation from the solution. A complete characterization of the material (XRD, XPS, FTIR , FE-SEM/EDS, BET and pH pzc ) revealed that L-GQS consisted of α-quartz, β-cristobalite, anorthoclase and small amount of iron oxy-hydroxides. Hydroxyl groups, Bronsted acid sites and Lewis acid sites on the surface of L-GQS all contributed to the atrazine adsorption, ozone decomposition and ·OH generation. The L-GQS catalyzed ozonation exhibited superior atrazine degradation and mineralization rates in a wide range of pH (3.0–9.0) and reaction temperatures (278 K–293 K). Also, an enhancement of DOC abatement was observed both in presence of natural organic matter isolates and natural water matrices (river water) when L-GQS was used. Finally, the degradation mechanism was proposed, based on the intermediates and by-products formation analyzed by LC-QTOF-MS/MS and ionic chromatography. Our results indicate that the L-GQS combined with stirring-assisted bubble column reactor could be utilized as an enhancement of ozone-based advanced oxidation processes .
研究领域:
环境科学
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化学工程
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水处理
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催化
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING SCIENCE
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2020
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IF 3.871
Hui Zhao,Jie Li,Lei Wang,Chunshan Li,Suojiang Zhang
A reaction/separation system composed of water-in-oil Pickering emulsion was constructed for the synthesis of methacrolein. The catalyst (diethanolamine acetate) aqueous solution was encapsulated in numerous emulsion droplets which were stabilized by dual stabilizer system and could be recycled and separated from product by filtration. The dual stabilizer system consisted of methyl–modified silica nanoparticles and monoglyceride. The effect of stabilizer system and dispersed phase on the Pickering emulsion properties were investigated, such as stability, rheological property, interfacial property and droplet size. The effect of emulsion properties on the catalytic performance was also studied. The strong stability, large interface area and proper particle layers of Pickering emulsion stabilized by dual stabilizer determined its excellent reactivity and catalyst efficiency. The Pickering emulsion showed good reaction stability in 8 cycles and could be used to produce methacrolein continuously for at least 72 h by filling in a column reactor.
研究领域:
化学工程
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催化
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材料科学
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化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）